Circular trough casting apparatus



Nov. 15, 1966 co o ET AL 3,284,859

CIRCULAR THOUGH CASTING APPARATUS Filed Oct. 14, 1965 5 Sheets$heet l I NVENTORS JOHN J. CONL 0N 001/6145 C. YFARLEY A 7' TORNEYS Nov. 15, 1966 Filed Oct. 14, 1963 J. J. CONLON ET AL 3,284,859

CIRCULAR TROUGH CASTING APPARATUS 5 SheetsSheet 2 INVENTORS ATTORNEYS J. J. CONLON ET AL 3,284,859

CIRCULAR TROUGH CASTING APPARATUS 5 Sheets-Sheet 3 Nov. 15, 1966 Filed Oct. 14, 1963 V/ Nu w \w m m2. mmm WM .w m c am M M Na H0 mm h R N, .V OI M II! i y l| M 3 A "Til; M II l l l l I I I Hl l I M/WWI I M llllllllllllllllll FIHIHH wk x QR Nov. 15, 1966 J. J. CONLON E AL 3,284,359

CIRCULAR TROUGH CASTING APPARATUS Filed Oct. 14, 1965 5 Sheets-Sheet 4.

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INVENTORS A TERA/5Y5 Nov. 15, 1966 J. J. CONLON ET AL 3,284,859

CIRCULAR THOUGH CASTING APPARATUS Filed Oct. 14, 1963 5 Sheets-Sheet 5 mus IN VENTORS JOHN .J. coma/v DOUGLAS c. YEA/P16) Unite Patented Nov. 15, 1966- ice 3,284,859 CIRCULAR TROUGH CASTIN G APPARATUS John J. Conlon, Westfield, and Douglas C. Yearley, Scotch Plains, N.J., assignors to Phelps Dodge Copper Products Corporation, New York, N.Y., a corporation of Delaware Filed Got. 14, 1963, Ser. No. 315,754 8 Claims. (Cl. 2257.3)

This invention relates to casting apparatus of the type in which the molten metal is continuously fed from a supply station into a mold consisting essentially of a circular trough rotating about a generally vertical axis of the circle, whereby the metal solidifies as it is carried by the rotating trough to a discharge station which removes the metal continuously as a rod, or the like.

The above-mentioned type of continuous casting apparatus has long been known in the art and is disclosed, for example, in US. Patent No. 359,349, dated March 15, 1887. Basically, it offers the advantage that the speed of casting is substantially unlimited, unlike casting with the use of a relatively short die (as in vertical casting) wherein dangerous and costly run-outs occur if the metal is drawn too rapidly from the restraining and supporting walls of the die. It also offers the advantage that the mold may be made of metal and will therefore have a much longer useful life than the ceramic or graphite dies conventionally used for continuous casting.

Despite its potential advantages, casting apparatus of the horizontal, circular trough type has not gone into significant use in practice. This has been due largely to the fact that such apparatus, as proposed heretofore, is incapable of adequately controlling the various factors which are involved in continuously casting rods, or the like, of good quality at high speed on a commercial scale. These factors include turbulence in the molten metal fed into the mold, the rate of solidification of the metal in the mold, cooling of the free upper surface of the solidifying metal, the tendency of this upper surface to oxidize during solidification, and other factors tending to impair the surface of the casting.

The principal object of the present invention is to provide an apparatus of the type described which overcomes the above-noted failings in prior apparatus of that type.

A continuous casting apparatus made according to the present invention comprises (a) a generally horizontal annular trough rotatable about a generally vertical axis and forming an endless mold open at the top, (b) a supply station including a container for molten metal having an outlet overlying the trough for delivering molten metal thereto, (c) means for rotating the trough about its axis in one direction for moving the delivered molten metal from the supply station, (d) a darn relative to which the trough is movable by the rotating means and disposed in the trough adjacent the region where the molten metal is delivered from the supply station, the dam being operable to limit flow of the molten metal in the trough in the direction opposite to its direction of rotation, (e) a cooling station extending along the trough in the direction of its rotation from a point adjacent the supply station and including cooling means located below the level of the top of the trough for cooling the latter and the molten metal therein, and (f) a discharge station located adjacent the trough and including means for continuously removing solidified metal from the rotating trough so that the latter is emptied before it reaches the molten metal supply station.

According to one feature of the invention, the apparatus also includes a gas-applying station overlying at least part of the cooling station and relative to which the trough is moved by the rotating means, this gas-applying station including means for maintaining a non-oxidizing atmos phere at the open top of the mold so as to prevent or at least substantially reduce oxidation of the free upper surface of the metal as it solidifies in the mold.

According to another feature of the invention, the apparatus also includes a dressing station located adjacent the rotating mold in advance of the molten metal supply station and including means for continuously applying to the previously emptied portion of the mold a material for resisting adhesion of the metal to be supplied to the mold. Preferably, a pre-heating station is provided between the discharge and dressing stations, whereby the mold surface is preheated to prevent sudden formation of surface skin incident to turbulent flow of molten metal into the mold at the supply station.

Still another feature of the invention resides in the provision of means for effecting a controlled cooling of the free upper surface of the solidifying metal in the mold, through a cooling surface engaging this free upper surface and moving therewith as the trough rotates, thereby in creasing the rate of solidification of the metal and improving the surface properties of the cast rod or bar.

These and other features of the invention may be better understood from the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of a preferred form of the new apparatus, with parts broken away;

FIG. 2 is an enlarged sectional view on the line 22 in FIG. 1, showing details of the molten metal supply station;

FIG. 3 is an enlarged sectional view on line 33 in FIG. 1, showing details of the cooling and gas-applying stations;

FIG. 4 is an enlarged sectional view on line 4-4 in FIG. 1, showing details of the discharge station;

FIG. 5 is an enlarged sectional view on line 55 in FIG. 1, showing details of the mold dressing station;

FIG. 6 is an enlarged sectional view on line 66 in FIG. 1, showing details of the means for direct cooling of the upper or free surface of the solidifying metal in the mold;

FIG. 7 is an enlarged sectional view on line 77 in FIG. 2, showing details of the lower end of the pouring spout which feeds the molten metal from the supply station, and

FIG. 8 is an enlarged sectional view, somewhat schematic, on the line 8-8 in FIG. 1, showing details of the pre-heating station.

The apparatus as illustrated comprises a stationary vertical post or axle 20 extending through a hub 21 having a close rotating fit on the axle (FIG. 1'). Hub 21 is adapted to be rotated on the axle at constant speed by a motor 22 connected through a variable speed transmission 23 and shaft 24 to a bevel gear 25 meshing with a large bevel gear 26, the latter being secured to hub 21.

The hub 21 has radiating spokes 28 secured at their outer ends, as by welding, to a fiat ring 29' of large diameter, for example, fifteen feet. Ring 29 is supported on horizontal rollers 30 spaced around the vertical axle 2t) and mounted on stationary posts 31 (FIGS. 2 and 3). A second flat ring 29a surrounds the ring 29 with a clearance and is supported on similar horizontal rollers 30a mounted on stationary posts $10!.

A mold in the form of circular trough 33 is located in the annular clearance between rings 29 and 29a, where it is supported at its inner and outer portions by the respective rings. As shown, the mold 33 is open at the top and has inwardly and outwardly extending flanges 34 and 34a resting on the rings 29 and 29a, respectively. These flanges are secured to the underlying rings by machine screws 35 (FIGS. 2 and 3) extending loosely through holes in the flanges. Thus, the concentric rings 29-29a are interconnected through the mold 33, and the arrangement is well adapted to accommodate thermal expansion and contraction of the parts as they rotate through zones of different temperatures.

The motor 22 operates through hub 21 and spokes 28 to rotate the interconnected concentric parts 29, 33 and 29a about the vertical axle as an axis, the rings 29- 29a riding on the respective rollers 30 and 3011. For simplicity and to avoid duplication, only some of the rollers 30-30a are illustrated, it being understood that they are provided in sufficient number to support the circular mold 33 adequately when it is loaded with the casting metal. It will also be understood that while the mold 33 may be rotated otherwise than as illustrated, it is desirable that it be mounted between two concentric rings 29-29a as shown, with the outer ring free to expand both generally and locally.

The molten metal is fed continuously into the rotating circular mold 33 from a supply station 40. The mold rotates counterclockwise as viewed in FIG. 1, thereby carrying the metal from supply station 40 through closely grouped stations including an overlying gas-applying station 50, an underlying cooling station 60 and an overlying cooling station 90. Other stations adjacent the rotating mold 33 (in their order in the direction of rotation) include a discharge station 70, a pro-heating station 110 and a dressing station 80. These various stations will now be described in detail.

Molten metal supply static-n As shown particularly in FIG. 2, the supply station 40 comprises a tun dish or container 41 in which a supply of molten metal to be cast is maintained. The container 41 is supported over the mold by a stationary bracket 42. The container 41 has a bottom opening in which the flanged upper end portion of a feed spout 43 is tightly but releasably secured by a nut 44, the spout extending downwardly through an enlarged opening 42a in the supporting bracket so that there is a clearance between the spout and the bracket. At its lower end portion 43a, the spout fits closely in the mold 33 to form a dam. A vertical passage 43b in the spout leads downwardly from the interior of container 41 and terminates short of the mold bottom, where it leads to a horizontal passage 43c extending forwardly in the direction of rotation of the mold (FIG. 7).

Thus, the molten metal is fed continuously through the spout 43 and enters the mold 33 from the spout passage 430 in the same direction as the mold travel, thereby reducing turbulence. At the same time, the lower end portion 43a of the spout acts as a dam to prevent backward flow of the molten metal in the rotating mold. The rate of supply of the molten metal to the mold may be adjusted in any suitable manner, as by means of a replaceable orifice member 45 seated at the upper end of the spout passage 43b.

The container 41 and an outward extension 41a thereof are provided with depending :pins 46 extending loosely through underlying holes 42b in supporting bracket 42. A compression spring 47 is coiled around each pin 46 and confined between the container 41-4111 and the bracket 42. These springs carry a substantial part of the weight of container 41 and its molten metal contents, so that the lower end portion 43a of the spout does not exert excessive downward pressure against the mold 33. Also, the springs 47 allow vertical movements of the container 41 and its spout 43 to accommodate any slight vertical movements of the mold as it rotates through the supply station 40. The clearances between pins 46 and the supporting bracket 42 allow lateral movements of the container and its spout incident to any variations in the radius of the mold 33 as it rotates through the supply station. I

In-other words, the parts 41-41a, 42, 4'6 and 47 form means supporting the darn 43a for both vertical and lateral movements with the mold trough 33, whereby the darn is maintained in efiective sealing engagement with the trough as it rotates.

Gas-applying station The station 50 comprises a housing 51 overlying the mold 33 'and supported by a stationary bracket 52. This housing is open at the bottom but has imperforate top and side walls which are elongated and slightly curved so that the housing extends over a substantial arc of the circular mold, starting at a point close to the molten metal supply station 40 (FIG. 1). As shown in FIG. 3, the bottom edges of the housing side walls 51a are provided with sealing members 53 resting on the flat rings 29 and 29a respectively, these sealing members being adapted to slide on the rings as the latter rotate. At its molten metal inlet end adjacent the supply station 40, the housing 51 is closed by a substantially air-tight curtain 54 of flexible material, such as asbestos, secured along its top and side edges to the adjacent walls of the housing. The bottom edge of curtain 54 conforms closely to the profile of the underlying moving parts 29-29a and 34-34a, so that it opposes these parts with only a slight clearance.

The opposite or outlet end of housing 51 is closed by a curtain similar to the curtain 54. Consequently, the housing forms a substantially air-tight chamber 55 to Which the free upper surface of the casting metal C in the mold 33 is exposed (FIG. 3).

A flexible tube 56 leads to the housing chamber 55 from a gas supply source such as a pressure tank (not shown). The gas is of the non-oxidizing type, preferably an inert gas (e.g., nitrogen or argon), and it is continuously supplied to the chamber at suflicient pressure and rate to prevent leakage of air into the chamber and to replace the gas leaking from the chamber. Thus, the parts 51, 53, 54 and 56 constitute means for maintaining a non-oxidizing atmosphere at the open top of the mold.

The stationary gas housing 51 extends over a sufficient arc of the rotating mold 33 so that the casting metal C emerges from the non-oxiding atmosphere only after its surface has solidified to a substantial thickness. The solidification of the casting metal is under control of the cooling means to be described presently.

By virtue of the gas-applying station 50, an oxide-free, high quality bar can be produced which has distinct advantages over conventional high electrical-conductivity copper bars rolled from refinery shapes. Refinery shapes are cast in open molds with one surface exposed to oxygen in the air. This surface absorbs oxygen and lacks ductility on subsequent rolling and drawing operations. For drawing into fine wire and for special applications, the refinery shape (usually a wire bar) must have the high oxygen surface removed. This is accomplished by either removing the high oxygen surface of the casting (called scalping) or removing the surface of the fabricated product (called shaving) or both. With the present system of continuous casting under controlled gas atmosphere, these procdures are not required.

In addition, when casting an alloy containing an element having a great affinity for oxygen, such as aluminum or zinc, the use of a controlled atmosphere over the solidifying metal will prevent the formation of dross which, if pi'lesent, could impair the mechanical properties of the a 0y.

Underlying cooling station The cooling station 60 comprises a stationary housing 61 located below the mold 33 and the gas housing 51, as shown in FIG. 3. Housing 61 has a length and curvature similar to the gas housing and extends along substantially the same arc of the mold as the latter housing. However, the housing 61 is open at the top and has an imperforate bottom as well as imperforate side walls. It is supported by posts 62. so as to maintain the top edges of its side walls in contact with the bottom surfaces of the flat rings 29 and 29a, respectively. At its entrance end adjacent the supply station 40, the housing 61 is closed by an end wall 63 which is cut to fit quite closely around the part of mold 33 which hangs from the flat rings 29 and 29a. The opposite or exit end of housing 61 is closed by an end wall (not shown) similar to the end wall 63. Thus, the housing 61 forms a substantially closed chamber 64 through which the hanging part of mold 33 moves as the mold rotates.

The cooling is effected by water supplied to a series of spray nozzles 65 extending through and supported by the bottom and side walls of housing 61. The water is supplied continuously under pressure to these nozzles from :a supply source (not shown) through pipes or tubes 66, the water being sprayed by the nozzles directly against the bottom and opposite'sides of mold 33. As shown in FIG. 1, the nozzles are spaced at frequent intervals along the length of the cooling station 69, so as to cool the rotating mold and solidify the casting metal at the desired rate. The cooling Water, after being sprayed against the mold, collects at the bottom of housing chamber 64 and is discharged through a pipe 67.

Overlying coolin'g station The station 90 (FIGS. 1 and 6) comprises a water cooled roller 90a mounted directly above the mold 33 in position to have the roller periphery contact the free upper surface of the casting metal C. The roller 90a has a graphite rim 91 adapted to fit snugly in the open upper portion of the mold, the rim closely surrounding a metal cylinder 92 to which the rim is fixed. Tubular shafts 93 and 93a extend axially through the opposite ends of cylinder 92 and are welded or otherwise secured to these ends, respectively. At their inner ends, the shafts 93 and 93a are similarly secured to the opposite ends of an inner cylinder 94 which is concentric to but substantially smaller than the outer cylinder 92, so that these cylinders form an annular flow space 92a. The hollow shafts 93 and 93a communicate with the opposite ends of this flow space, through holes 95, and extend outwardly through the opposing side walls of gas housing 51 in which roller 90a is located. These side walls 51a have sealing collars 51b in which shafts 93 and 93a are rotatable.

The cooling roller 90a and its axial shafts 93-93a are mounted for rotation on a stationary frame 96 extending transversely of and above the gas housing 51. The transverse frame 96 has at its inner end a depending leg forming a chamber 97 into which the open outer end of shaft 93a projects. This shade is rotatable in a sealing bushing 97a secured in the chamber wall through which shaft 93a extends. A flow passage 96a in the frame 96 extends from chamber 97 to a Water discharge hose 98. At its outer end, the frame 96 has a second depending leg forming a chamber 99 into which the open outer end of shaft 93 projects from a sealing bushing 100. A hose 191 continuously supplies cooling water to chamber 99 from a supply source (not shown).

The outer end of transverse frame 96 has a dovetail 96b closely received in a vertical dove-tailed groove 102a in a stationary post 102, whereby the frame 96 is movable vertically relative to the post but is otherwise held against movement. The frame is supported vertically by depending rods 104 straddling the gas housing 51 and provided at their lower ends with rollers 105 resting on the flat rings 29 and 29a, respectively. The lower portion of each rod 104 has two branches straddling the adjacent shaft 93 or 93a, each branch being forked, as shown at 104a, to receive a corresponding roller 105. The upper end of each supporting rod is slidable in a hollow boss 960 of frame 96 and is secured in an adjusted position in this boss by a set screw 106.

A gear 108 is secured to shaft 93 and meshes with a gear 109 driven by an electric motor 110 which is mount- 6 ed on the outer leg of frame 96. The motor 110 drives the cooling roller a in a direction and at a constant speed such that the periphery of the roller, where it contacts the free upper surface of the casting metal C in the rotating mold 33, moves in the same direction and at the same liner speed as the mold, thereby avoiding relative movement between the free upper surface of the casting metal and the contacting surface of the roller periphery. Such relative movement would be objectionable because it would develop frictional forces acting against the surface of the casting and cause hot tears and cracks in the surface.

During this rotation of cooling roller 90a, the cooling liquid flows from supply hose 101 through chamber 99, shaft 93, the annular flow space 92a in roller 90a, shaft 93a, chamber 97 and passage 96a to the discharge hose 98. As a result, the roller 90a is continuously cooled as it rotates in contact with the free upper surface of the casting metal in the rotating mold 33. Thus, the cooling roller forms in effect a roller gate located in the path of the casting metal; and as the molten metal passes under the roller gate, its cooling action forms a solid skin across the top surface of the metal. This establishes a uniform cross-section of the cast rod or bar and tends to eliminate the ripples characteristic of an unrestricted cast surface.

The set screws 106 allow adjustment of the cooling roller 99a to the proper height in mold 33, for providing the aforesaid surface contact with the casting metal. Thereafter, with the mold rotating at constant speed, the roller 90a will follow any vertical deviations of the rotating mold structure passing through the station 90, since the supporting rollers will ride up or down with those deviations (as will the gas housing 51 due to flexibility of its supporting bracket 52). If desired, the shaft bushings 511) may be made flexible to accommodate vertical movements of cooling roller 90a relative to the gas housing 51. Since the shafts 93-93a are slidable endwise in their bushings 98 and 160, the cooling roller 99a can move laterally to accommodate any deviations in the radius of the circular mold as it moves through the station 90.

In some cases, where surface quality of the cast metal is not particularly important, th station 90 for direction cooling of the free upper surface may be omitted. Also, in cases Where the casting metal is one which is not easily oxidized at the casting temperatures, the gas-applying station 50 may be omitted. In general, however, it is advantageous to use at least one of these stations.

Cast metal discharge station The discharge station 70 (FIGS. 1 and 4) is located well beyond the cooling station 60, so that the solidified casting metal C may cool further but at a lower rate before being discharged from the mold 33. Its discharge is effected by means comprising a pick-up wedge 71 having a close sliding fit in the mold, where it is secured by a stationary bracket 72. The wedge 71 has its pointed edge facing in the direction opposite to the direction of rotation of the mold, so that rotation of the latter causes the cast bar C to slide up the ramp 71a formed by the wedge.

From the high end of wedge 71, the bar C passes to a stationary elongated frame 73 extending generally tangentially of the circular mold and above its level, this frame being secured by stationary brackets 74. The frame is hollow and carries an upper set of rollers 75 and a lower set of rollers 76, the latter serving to support the bar C as it moves through the frame between the opposite sides of the frame, which guide the bar.

From the frame 73, the bar or rod C passes to a rolling mill or coiler (not shown).

Mold preheating station The station comprises a series of stationary gas burners 111, 112, 113 and 114 (FIGS. 1 and 8). The burners 111 and 114 are mounted above and below, respec- 7 tively, the mold trough 33, while the burners 112 and 113 are mounted at opposite sides of the trough. The top burner 11]. is supported by a stationary bracket 115, and the other burners are supported by corresponding brackets (not shown). Each burner is continuously supplied with a combustible gas through a hose 116.

As the mold 33 rotates, the flames from the burners impinge upon the inner surfaces of the mold from above and also upon its outer surfaces at the opposite sides and the bottom. In this Way, the empty mold is preheated when it arrives at the molten metal supply station 40, thereby preventing sudden formation of surface skin from the turbulent flow of metal entering the mold trough. It is important to prevent such sudden formation of surface skin under turbulent conditions, as it will cause laps, seams and cold shot in the initially formed chill layer of the casting and thereby impair the quality of the finished product.

Alternatively, the cooling of the molten metal entering the mold may be retarded initially by spacing the cooling station 60 from the supply station 40 or by making the mold of a material having a low heat conductivity. By these measures, any surface skin initially formed adjacent the supply station under the turbulent conditions is remelted by the body of superheated liquid metal, and the final formation of surface skin does not begin until the turbulence has ceased by settling of the liquid metal.

Mold dressing station The station 80 comprises a stationary vertical support 81 extending through a bracket 82 which may be secured in any desired vertical position on the support by a set screw 83. A horizontal tube 84 rests on the bracket 82, to which the tube is releasably secured by a clamping plate 85. Tube 84 has a downwardly extending portion terminating in a nozzle 86 aimed directly into the mold trough 33.

Through the tube 84, a dressing is continuously applied to the inner surfaces of the empty mold before it arrives at the molten metal supply station 40. This dressing, delivered from a supply source (not shown), will usually be a carbonaceous material. It may be applied to the mold surface by suspending the material (such as graphite powder) in a volatile organic liquid (such as alcohol) sprayed through the nozzle 86; or a rich gas or oil may be supplied through tube 84 to the nozzle 86 as a burner, so that the flame deposits soot on the mold surfaces.

The dressing thus applied at station 80, in advance of the molten metal supply station 40, prevents adherence of the casting to the mold, reduces surface imperfections in the casting, and provides lubrication to afford a better sliding contact between the inner surfaces of the mold and the darn 43a at the supply station. By providing the preheating station 110 in advance of the dressing station, the dressing is applied to relatively hot surfaces of the mold, which is advantageous.

Operation The operation of the casting apparatus as illustrated will be apparent from the foregoing. It may be operated at high speed for economical casting of various metals and alloys. For example, 20,000 pounds of copper per hour may be cast into a bar having a cross-sectional area of 1 /2 square inches, the velocity of the liquid metal flow into the trough 33 being as high as 60 inches per second as compared to a mold velocity of 12 inches per second.

Of course, the cross-sectional area of the mold trough 33 may take various shapes depending upon the desired cross-section of the cast bar or rod.

We claim:

1. Continuous casting apparatus comprising a generally horizontal annular trough rotatable about a generally vertical axis and forming an endless mold open at the top, a supply station including a container for molten metal having an outlet overlying the trough for delivering molten metal thereto, means for rotating the trough about said axis in one direction relative to said outlet for moving the delivered molten metal in said one direction from the supply station, a dam relative to which the trough is movable by said rotating means, the dam being disposed in the trough adjacent the region where the molten metal is delivered from said outlet and being operable to limit flow of the metal in the trough in the direction opposite to said one direction, a cooling station extending along the trough in said one direction from a point adjacent the supply station and relative to which the trough is movable by said rotating means, the cooling station including cooling means located below the level of the upper part of the trough for directly cooling the lower part of the trough and said molten metal delivered thereto, a gas-applying station overlying at least part of said cooling station and relative to which the trough is movable by said rotating means, the gas-applying station including means for maintaining a non-oxidizing atmosphere at said open top of the mold, and a discharge station located adjacent the trough in said one direction from the cooling'station and in said opposite direction from the supply station, said discharge station including means for continuously removing solidified metal from the trough as the latter is rotated about said axis.

2. Continuous casting apparatus comprising a generally horizontal annular trough rotatable about a generally vertical axis and forming an endless mold open at the top, a supply station including a container for molten metal having an outlet overlying the trough for delivering molten metal thereto, means for rotating the trough about said axis in one direction relative to said outlet for moving the delivered molten metal in said one direction from the supply station, a dam relative to which the trough is movable by said rotating means, the dam being disposed in the trough adjacent the region where the molten metal is delivered from said outlet and being operable to limit flow of the metal in the trough in the direction opposite to said one direction, resilient means mounting said dam for vertical and lateral movements, to accommodate deviations in the symmetry of the trough relative to said axis, a cooling station extending along the trough in said one direction from a point adjacent the supply station and relative to which the trough is movable by said rotating means, the cooling station including cooling means located below the level of the top of the trough for cooling the trough and said molten metal delivered thereto, a discharge station located adjacent the trough in said one direction from the cooling station and in said opposite direction from the supply station, said discharge station including means for continuously removing solidified metal from the trough as the latter is rotated about said axis, and a dressing station adjacent the mold and located in said one direction from the discharge station and in said opposite direction from the supply station, said dressing station including means for applying to the mold a material for resisting adhesion of said metal to the mold.

3. Continuous casting apparatus comprising a generally horizontal annular trough rotatable about a generally vertical axis and forming an endless mold open at the top, a supply station including a container for molten metal having an outlet overlying the trough for delivering molten metal thereto, means for rotating the trough about said axis in one direction relative to said outlet for moving the delivered molten metal in said one direction from the supply station, a dam relative to which the trough is movable by said rotating means, the dam being disposed in the trough adjacent the region where the molten metal is delivered from said outlet and being operable to limit flow of the metal in the trough in the direction opposite to said one direction, a cooling station extending along the trough in said one direction from a point adjacent the supply station and relative to which the trough is movable by said rotating means, the cooling station including cooling means located below the level of the upper part of the trough for directly cooling the lower part of the trough and said molten metal delivered thereto, means engagable with the free upper surface of molten metal in the trough and movable therewith for cooling said surface, and a discharge station located adjacent the trough in said one direction from the cooling station and in said opposite direction from the supply station, said discharge station including means for continuously removing solidified metal from the trough as the latter is rotated about said axis.

4. Continuous casting apparatus comprising a generally horizontal annular trough having a general vertical axis and forming an endless mold open at the top, the trough having horizontal flanges along its opposite sides, a pair of flat rings concentric to said axis and defining an annular space between said rings, the trough being mounted in said space for rotation about said axis on said rings, means securing said flanges to respective ones of said rings to allow radial movements of the flanges relative to the rings, means for rotating the trough about said axis on said rings, a supply station including a container for molten metal having an outlet overlying the trough for delivering molten metal thereto, a dam relative to which the trough is movable by said rotating means, the dam being disposed in the trough adjacent the region where the molten metal is delivered from said outlet and being operable to limit flow of the metal in the -trough in the direction opposite to the direction of rotation of the trough by said rotating means, a cooling station extending along the trough in said direction of rotation from a point adjacent the supply station, the trough being rotatable relative to the cooling station, the cooling station including means for cooling the trough and the molten metal therein, and a discharge station located adjacent the trough and including means for continuously removing solidified metal from the trough as the latter is rotated by said rotating means.

5. Continuous casting apparatus according to claim 3, comprising also means mounting said surface cooling means for vertical movements to accommodate vertical movements of the trough as it rotates.

6. Continuous casting apparatus according to claim 3, comprising also means mounting said surface cooling means for lateral movements to accommodate radial deviations of the trough as it rotates.

7. Continuous casting apparatus according to claim 1, comprising also means mounting said dam for vertical movements to accommodate vertical movements of the trough as it rotates.

8. Continuous casting apparatus according to claim 1, comprising also means mounting said dam for lateral movements to accommodate radial deviations of the trough as it rotates.

References Cited by the Examiner UNITED STATES PATENTS 359,349 3/1887 Daniels 22--57.3 1,982,763 12/1934 Russell et a1. 22192 2,099,208 11/1937 Horsfall et a1. 22-'57.3 X 2,383,310 8/1945 Hazelett 22200.1 X

OTHER REFERENCES The Iron Age, Continuous Casting, April 11, 1940, pp. 45 and 46.

J. SPENCER OVERHOLSER, Primary Examiner.

R ANNEAR, Assistant Examiner, 

1. CONTINUOUS CASTING APPARATUS COMPRISING A GENERALLY HORIZONTAL ANNULAR TROUGH ROTATABLE ABOUT A GENERALLY VERTICAL AXIS AND FORMING AN ENDLESS MOLD OPEN AT THE TOP, A SUPPLY STATION INCLUDING A CONTAINER FOR MOLTEN METAL HAVING AN OUTLET OVERLYING THE TROUGH FOR DELIVERING MOLTEN METAL THERETO, MEANS FOR ROTATING THE TROUGH ABOUT SIDE AXIS IN ONE DIRECTION RELATIVE TO SAID OUTLET FOR MOVING THE DELIVERED MOLTEN METAL IN SAID OND DIRECTION FROM THE SUPPLY STATION, A DAM RELATIVE TO WHICH THE TROUGH IS MOVABLE BY SAID ROTATING MEANS, THE DAM BEING DISPOSED IN THE TROUGH ADJACENT THE REGION WHERE THE MOLTEN METAL IS DELIVERED FROM SAID OUTLET AND BEING OPERABLE TO LIMIT FLOW OF THE METAL IN THE TROUGH IN THE DIRECTION OPPOSITE TO SAID ONE DIRECTION, A COOLING STATION EXTENDING ALONG THE TROUGH IN SAID ONE DIRECTION FROM A POINT ADJACENT THE SUPPLY STATION AND RELATIVE TO WHICH THE TROUGH IS MOVABLE BY SAID ROTATING MEANS, THE COOLING STATION INCLUDING COOLING MEANS LOCATED BELOW THE LEVEL OF THE UPPER PART OF THE TROUGH FOR DIRECTLY COOLING THE LOWER PART OF THE TROUGH AND SAID MOLTEN METAL DELIVERED THERETO, A GAS-APPLYING STATION OVERLYING AT LEAST PART OF SAID COOLING STATION AND RELATIVE TO SHICH THE TROUGH IS MOVABLE BY SAID ROTATING MEANS, THE GAS-APPLYING STATION INCLUDING MEANS FOR MAINTAINING A NON-OXIDIZING ATMOSPHERE AT SAID OPEN TOP OF THE MOLD, AND A DISCHARGE STATION LOCATED ADJACENT THE TROUGH IN SAID ONE DIRECTION FROM THE COOLING STATION AND IN SAID OPPOSITE DIRECTION FROM THE SUPPLY STATION, SAID DISCHARGE STATION INCLUDING MEANS FOR CONTINUOUSLY REMOVING SOLIDIFIED METAL FROM THE TROUGH AS THE LATTER IS ROTATED ABOUT SAID AXIS. 